Spark-plug.



1.]. SMITH, JR.

SPARK PLUG.

APPLICATION FILED NOV. 13. 19:5.

11 6,39 Patented May15,1917i.

A TTORNEYS a spark plu the terminals to which FFIQOE.

JOSEPH JOHN SMITH, JR., OF BENTON HARBOR, MICHIGAN.

Specification of Letters Patent.

Patented May 15, 1917.

Application filed November 13, 1915. Serial No. 61,323.

Toall whom it may concern:

Be it known that I, JOSEPH JOHN SMITH, Jr., a citizen of the United States, and a resident of Benton Harbor, in the county of Berrien and State of Michigan, have invented a new and useful Improvement in Spark-Plugs, of which the following is a specification.

My invention relates to improvements in spark plugs and it consists in the combinations, constructions and arrangements. herein described and claimed.

An object of my invention is to provide having removable terminal points, where y, when the latter are fouled they can be removed and be replaced by clean tips.

A further object of my invention is to provide a spark said tips giving a greater sparking area than the ordinary terminal.

A further object of my invention is to provide a spark plug having removable tips, the terminals being so arranged that when the core of the spark plug is turned relatively to the shell, the spark gap may be adjusted.

. Other objects and advantages will appear in the following specification, and the novel features of the invention will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawing forming part of this application, in whic j Figure 1 is a sectional view through the device,

Fig. 2 is a side view of one of the termina s Fig. 3 is a sectional view through one of the tips,

Fig. 4 is a sectional view through one of a tip has been applied,

Fig. 5 is a side view showing the tip as: sembled on the terminal, this view also showing a modifiedform of tip,

Fig. 6 is a sectional view of the tip shown in Fig. 5,

Fig. 7 is a section on the line 7-7 of Fig. 1, and

Fig. 8 is a sectional view similar to Fig.

7, but showing the parts in another pos1- tion, whereby the spark gap is adjusted.

Fig. 9 is a view of a modified form of plug having removable tips,

- tion, that is to say,

or recede from one the device, showing additional means for adjusting the spark gap.

In carrying out my invention I make use of spark plugs of any ordinary shape, in which an outer shell 1 incloses a core 2 of insulating material, said outer shell having a reduced portion 1 which is threaded to enter the spark plug opening of the cylinder of an internal combustion engine.

Secured to the shell 1 is a Z-shaped terminal 3, while the terminal 4 which is carried by the core 2 is also preferably Z- shaped, and, as shown in Fig. 1 is disposed eccentrically of the core, that is to say, it is not run through the center of the core. Each of the terminals 3 and 4 is threaded at its ends, as shown in Fig. 2, at 3*. Furthermore, the opposite sides are flat or cut away, as shown at 3". A tip, which in this instance, is an internally threaded sleeve 4 is provided and may be screwed onto the end 3 of the terminal. screwed on, it may be pinched with a pair of pliers or any other suitable instrument, so as to flatten the sleeve thereby preventing it from coming ofl from the terminal.

In Figs. 5 and 6 I have shown a modified form of the device in which the terminals 5 and 6 are notched as shown at 5 and 6. Tips 7 and 8 are provided for the terminals 5 and 6 respectively, the tip 8 being provided with an end portion 8*, while the tip 7 is merely an unthreaded sleeve which surrounds the laterally bent end of the terminal 5. After these tips are placed on their respective terminals, they are crimped 0r pinched so as to enter thenotohes and thereby be retained on the terminals. In this form of the arrangement there is a large sparking surface which tends to give better ignition.

The arrangement of the terminals in the manner shown in Fig. 1 gives another functhe spark gap may be adjusted by simply adjusting the position of the core with respect to the shell, so it will be observed that when the shell or core is turned the terminals will of course approach another depending upon the distance and direction in which the parts have been turned.

From the foregoing description of the various parts of the device, the operation thereof may be readily understood.

The advantage of having the terminals re- When it has been.

movable is that after the terminals become foul they can be removed and new ones put in their places. In order to remove the terminals it is only necessary to pinch the sleeves back into their oiginal shape by means of a pair of pliers when they can be readily unscrewed and replaced by new ones.

The adjustment of the terminals in the manner described obviates the necessity of bending the terminals as is now often done, and thus reduces the liability of breaking the terminals through such bending.

In Fig. 9 I have shown a sleeve or tip I as being mounted eccentrically of the terminals 3. It is obvious that by turning the sleeves of the opposed terminals the spark gap may be varied without the necessity of moving the plug.

1. In a spark plug construction, a pair of opposed terminals, a tip for each terminal,

said terminals being threaded at their ends v and beingprovided with cut-away portions, each of said tips being threaded internally to engage the threaded end of the terminal and adapted to be compressed into the cutaway portion whereby the distortion Will lock the tip to the terminal. 7

2. In a spark plug construction, a pair of opposed terminals, the ends of the said terminals extending in parallel directions, each of said ends being threaded, a sleeve for each terminal having a bore threaded internally and arranged eccentrically of the sleeve, whereby the sleeve or'tip on adjacent terminals may be brought nearer together or farther apart by the rotation of either or both of said sleeves on said terminals.

JOSEPH JOHN SMITH, JR.

\Vitnesses:

WILLIAM S. KNIsELY, WILLIAM P. HOLDER. 

